Mooseberry joked on a another thread that he'd like to put the human and alien teams and bases in a very small box and let them rip at each other (at least I think he was joking

).
So ok, not a tiny little box, but how about something reasonably small, like the storage room with the suspended platform on Arachnid?
Yes, I mean that would be the entire map. Place aliens at one end, humans at another. When and if they reach S2 they can try taking over the platform.
The Arachnid room is just an example, I'm sure others can be found. Regardless, here are some things that could make such a map playable:
* I've already given you an idea about the size, I hope. Other comparisons: twice the ATCS courtyard; the human default room on Niveus + the next room; the storage room on Tremor; the human default room on Karith etc.
* The room should feature obstacles that would limit aliens from fast access from one side to another, and at the same time prevent humans from firing clear across it. Such as stacks of storage boxes, rows of pillars, low roofs with protrusions, pipes etc. Think of the room next to the human default on Transit, or the room with the big transparent pipe on Nexus. It would be nice though to find a happy medium between limitations and small zones of free movement. For both aliens' and humans' sake.
* Lighting may be important. Would low light help prolong or hasten the end of the game? Which would be desirable?
* It's not out of the question to add one or two small rooms or balconies or alcoves to make things more interesting.
And the most important question: would such a small map be playable? I think so, and I think maps like Mission One or Nano have proven that, and this map genre has the potential to become very interesting.